The Third Generation Partnership Project (3GPP) standard Release 4 architecture utilizes a mobile switching centre server (MSC-S) as controlling element and a media gateway node (MGW) to do the data plane handling of packet-based voice calls in the circuit switched (CS) domain of a core network (CN).
The MSC-S contains the mobility management and the call control logic without residing in the media pathway of real time communication services such as voice streams or video streams. The media pathway passes through one or more MGWs. The MGW is an element maintaining a call connection and performing switching function when required. The MGWs establish, manipulate, and release the media streams. The way the MSC-S controls the MGW is defined by the media gateway control protocol framework, also referred to as the H.248 protocol framework (MEGACO). Further control signaling occurs between a radio network controller (RNC) and the MSC-S.
Generally mobile data traffic volumes are steadily increasing. Reasons for this can be, e.g., users watching online videos. In some regions, the data traffic volumes are exceeding the volumes for CS voice data traffic already today, while all others regions show a similar trend. With the availability of the 4G radio technology (LTE) this trend can be expected to increase.
In this light, a MSC-S and MGW are supporting IP transport already today. For example, the MSC-S and the MGW of today already support packet based functionality via internet protocol (IP) for data transport between nodes in the core network. Also the CS RNCs and base station controllers (BSCs) support IP based data transport. This is known as “A-interface over IP” (AoIP) and “Iu over IP”. In networks which are predominantly based on packet traffic in the packet switched (PS) domain, maintaining the CS domain for voice traffic in the CN may become complex and costly.
Accordingly, a need exists to provide efficient routing techniques for data packets of real time communication services of a call.